Underwater sleds



May 5, 1964 Filed Oct. 22, 1962 G. W. M INVALE UNDERWATER SLEDS 4 Sheets-Sheet l INVENTOR.

GEORGE W. MC INVALE ATTORNEY May 5, 1964 G. w. MCINVALE UNDERWATER SLEDS 4 Sheets-Sheet 2 Filed Oct. 22, 1962 I. I\ n wllllb INVENTOR. GEORGE W. MC INVALE ATTORNEY y 1964 G. w. MCINVALE 3,131,664

UNDERWATER SLEDS Filed Oct. 22, 1962 4 Sheets-Sheet 3 FIG. 5

INVENTOR.

GEORGE W. MC INVALE ATTO R NEY G. W. M INVALE UNDERWATER SLEDS 4 Sheets-Sheet 4 INVENTOR. GEORGE W. MC INVALE ATTORNEY May 5, 1964 Filed Oct. 22, 1962 FIG. 7

FIG. [3

United States Patent 3,131,664 UNDERWATER SLEDS George W. McInvale, Irving, Tex., assignor to Ling-Temco-Vought, Inc. Filed Oct. 22, 1962, Ser. No. 231,900

3 Claims. (Cl. 11416) This invention relates in general to certain new and useful improvements in marine vehicles and, more particularly, to a small underwater sled adapted for use by scuba divers.

In many types of underwater diving operations, it is often desirable and sometimes essential for the diver to travel over substantial distances to reach the locale in which the work or other effort is to be carried out. In scuba diving, the amount of time which can be spent under Water is usually limited, in part, by the physical stamina of the diver and, in part, by the oxygen supply in the divers oxygen tanks. Consequently, if a scuba diver is employed in doing some form of underwater engineering work, assisting in the salvage of sunken vessels, or pursuing some sporting avocation, such as underwater exploration marine photography, it is usually desirable to provide the diver with some means of underwater transportation by which it is possible to reach the locale of activities as quickly as possible from the shore or other point of entry into the water. Such means of transportation not only conserves the drivers physical energy, but also reduces the drain upon the oxygen supply in the drivers oxygen tanks, so that the diver may extend his activities to underwater locations which might otherwise be beyond normal range from a given starting point. Moreover, by use of such a means of transportation, the diver will be able to reach the desired objective much more quickly and, thus, have a greater amount of time under water to carry out the assigned tasks or desired activities.

Underwater vehicles of this type are not only valuable in the purely recreational aspects of scuba diving or the gainful occupations of marine salvage and underwater construction work, but also have substantial military value in assisting the underwater preparatory efforts incident to an amphibious landing, the exploratory charting of mine fields, the underwater assault upon submarine bases, and similar underwater demolition projects. For such purposes, it is possible for a small power boat or submarine to stand off-shore at a safe distance from shore batteries and discharge the divers, who can then, through the use of rapidly traveling underwater vehicles, traverse the distance to the objective while entirely submerged, complete the underwater mission, and return to the offshore vessel with such speed and rapidity as to insure complete safety and surprise. In addition, it is highly desirable that the underwater vehicle be shaped somewhat like a marine creature, such as, for instance, a porpoise and be capable of executing maneuvers similar to the swimming-pattern of a porpoise in order to deceive an observer in case there is need for deception.

It is, therefore, the primary object of the present invention to provide an underwater vehicle which is capable of controlled submersion to various desired depths and which can move beneath the surface of the water at a comparatively rapid rate of speed with an unusually high degree of maneuverability.

It is another object of the present invention to provide an underwater vehicle of the type stated which will transport a scuba diver from place to place beneath the surface of the water in a rapid, efiicient, and fully controllable manner.

It is an additional object of the present invention to provide an underwater vehicle of the type stated which, in

general appearance and contour, closely resembles large marine animals, such as porpoises, and can be readily made to maneuver through water in a manner simulating the movements of a porpoise, so that, when viewed from even relatively close proximity, will create an effec tive illusion such that the identity of the vehicle will not be readily recognized by the observer.

It is a further object of the present invention to provide an underwater vehicle of the type stated which is electrically driven and, therefore, capable of movement through the water in a substantially silent and relatively undetectable manner.

It is also an object of the present invention to provide an underwater vehicle of the type stated, the hull of which is constructed of non-metallic materails and is, therefore light in weight, inexpensive and realtively safe against detection by presently known underwater detection devices.

. It is a further object of the present invention to provide an underwater vehicle of the type stated in which the occupant is subjected to conditions of temperature and pressure which correspond to ambient conditions so that the occupant of the vehicle can, for any reason, immediately leave the vehicle or return to it without encountering problems of decompression or the like.

With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawings:

FIG. 1 is a perspective view of an underwater vehicle constructed in accordance with and embodying the present invention;

FIG. 2 is a side elevational view of the underwater vehicle shown in FIG. 1;

FIG. 3 is a longitudinal sectional view taken along line 33 of FIG. 1;

FIG. 4 is a transverse sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a horizontal sectional view taken along line 55 of FIG. 2;

FIGS. 6, 7, and 8, are transverse sectional views taken along lines 66, 7-7, and 8-8, respectively, of FIG. 5;

FIGS. 9 and 10 are fragmentary sectional views taken along lines 99 and 1tl10, respectively, of FIG. 5;

FIG. 11 is a fragmentary sectional view takena long line 11-41 of FIG. 9;

FIG. 12 is a fragmentary side elevational view of the submersion valve control system forming a part of the present invention;

FIG. 13 is a fragmentary sectional view taken along line 1313 of FIG. 4; and

FIG. -14 is a fragmentary sectional view taken along line 1414 of FIG. 13.

Referring now in more detail and by reference characters to the drawings, which illustrate a preferred embodiment of the present invention, A designates a boat or marine vehicle having a hull 1 which is formed in any conventional manner from fiber glass and a waterproof synthetic resin. Inasmuch as the fabrication of fiber glass boat hulls has become a well-established conventional practice, anyone familiar with this art could readily construct the hull *1 as shown in the drawings by conventional techniques and, therefore, it is unnecessary to outline in detail the manufacturing steps and procedures thereof. It is sufficient for present purposes to point out that the hull 1 has a blunt-nosed, arcuate shape somewhat resembling a porpoise-shaped sled. Internally, the hull 1 is integrally provided, adjacent its forward end, with a vertical crosswall 2 which, in cooperation with the top wall 3 and bottom wall 4, defines a closed for- Patented May 5, 1964 ward compartment 5. The top wall 3 is provided with a relatively large semi-circular opening 6 which is closed by a marginally gasketed water-tight lid 7 held in place by conventional countersunk fasteners 8. The upper portion of the wall 2 is preferably inclined forwardly at a slight angle, thereby forming a dashboard or instrument panel 9. Mounted in water-tight relationship in the instrument panel 9 is a tachometer 10, an ammeter 11, a volt meter 12, a control rheostat 13, a bank-and-turn indicator 14, a depth-pressure gauge 15, a directional compass 16, an air-pressure gauge 17, a water-pressure gauge .18, a hydrogen-pressure gauge 19, and an oxygen-pressure gauge 20, all as best seen in FIG. 4 and for purposes presently more fully appearing. Rearwardly of the wall 2 and along its two sides, the hull 1 is provided with two parallel interior side walls 21, 22, which, in etfect, define an occupant-compartment C and two longitudinally extending laterally disposed ballast chambers 23, 24, which respectively open downwardly to admit water through a series of transversely elongated parallel slots 25. These slots are optionally closed by an ar-cuate plate-like slide valve 26 shiftably mounted in a slide frame 27 and provided with a series of transversely extending slot-like openings 28. Rigidly secured to, and extending forwardly from, the slide valve 26 is an actuator bar 2? provided at its forward end with rack-like series of teeth 30 which mesh with an operating gear 31 pinned upon a shaft 32 which is journaled in, and extends through, the side walls 21, 22, being bent downwardly in the provision of two rocker arms '33, 34, which are integrally connected across the bottom of the occupant-compartment C by a hand rod 35. In this connection, it should be noted that, although the slide valves 26 are inclined to conform to the general contours of the underside of the hull 1, the actuator bar 2? is fitted at a compensating angle so that the rack teeth 30 will mesh with the gear 31 along lines which are truly parallel to the axis of rotation of the shaft 32. Moreover, the outer ends of the shaft 32 are journaled in conventional bearings 36 which are suitably mounted in the interior faces of the ballast compartments 23, 24, all as best seen in FIG. 8.

At its rearward end, the hull 1 is integrally provided with a transversely extending vertical back wall 37 which is centrally provided with a tubular housing 38 extending fore-and-aft symmetrically along the centerline of the hull .1 and terminating rearwardly from the back wall 37 in an end wall 39. At its forward end, within the oc cupant-compartment C, the housing 38 is provided with an annular flange 40 for receiving a gasketed closure plate 41 which is removably held in place by bolts 42, thereby providing an accessible, but watertight, compartment 43 which contains a relatively large and powerful, direct current motor 44 secured therein by flanges 45, 46, and a plurality of hold-down bolts 47. The motor 44 is provided with a rearwardly extending drive shaft 48 which is journaled in a conventional watertight rotary seal 49 mounted in the end wall 39. On its rearwardly projecting or external end, the shaft 48 is provided with a conventional marine propeller 50 which is operatively disposed within a cylindrical propeller guard 51 supported in spaced relation from and rearwardly of the tapering rear portion of the housing 33 by means of support rods 52, all as best seen in FIG. 3.

Rearwardly of the back wall 37, the hull 1 is integrally provided with two laterally spaced bosses 53, 54, which are respectively provided with juxtaposed bearings 55, 56, for operatively supporting the outer ends of shafts 57, 58, which extend transversely in coaxial alignment with each other and project inwardly through watertight bearings or rotary seals 59, 60, mounted in the housing 38 so that the interior ends of the shafts 57, 58, are located within the compartment 46.

Formed integrally with the bottom wall 4 and extending substantially along the longitudinal centerline thereof is a short downwardly projecting keel K which, although not absolutely necessary, nevertheless serves to add hydrodynamic stability to the marine vehicle A. Also integrally formed with and projecting upwardly from the bottom wall 4, within the occupant-compartment C is a hollow couch-like platform P which includes a forward wall 61, a top wall 62, side walls 63, 64, a V-shaped yoke wall 65, and rear walls 66, 67. As will be seen by reference to FIG. 5, the yoke wall 65 and the rear walls 66, 67, are so arranged that the rearward portion of the platform P is bifurcated to accommodate the hips and thighs of the occupant. Similarly, at the forward portion of the platform P, the top wall 62 and front wall 61 are curved upwardly and narrowed to form a chin rest elemen-t 68, as best seen in FIGS. 3 and 4. Perferably, though not necessarily, the upper face of the top wall 62 is provided with a closed cell sponge rubber pad 69 which is adhesively secured in place and will underlie the chest and abdomen of the occupant so as to afford a greater measure of physical comfort when the occupant is riding in the marine vehicle A.

In the region of the occupant-compartment C, the top wall 3 is provided with a relatively large somewhat rectangular opening 70 through which the occupant may enter the occupant-compartment C and dispose himself in reclining position upon the couch-like platform P. This opening 70 is provided with a transparent canpoy 71 which is deformed upwardly in its central portion in the provision of a so-called bubble 72 which is of such size and shape as to allow adequate clearance for the occupants head and the oxygen tanks T which are normally strapped to his back. The canopy 71 is releasably and hingedly secured in place by several pairs of axially aligned hinge-knuckles 73 which fit loosely and embracingly around complementary hinge-knuckles 74 rigidly secured to the top wall 3 along the two longitudinal margins of the opening 70. Slidably supported upon the inwardly presented faces of the side walls 21, 22 by means of bosses 75 are locking rods 76 which have laterally projecting L-shaped pintle elements 77 to shift axially into the sets of hinge-knuckles 73, 74, substantially in the manner shown in FIG. 13. At their forward ends, the rods 76 are provided with inwardly extending hand grips 78 so that the occupant, once he is in reclining position within the occupant-compartment C, can reach forward and manually grasp either or both of the hand grips 78 to manipulate the rods 76. If the rod 76 which is adjacent to the occupants right hand is pushed forwardly so that the pintle elements 77 thereof are disengaged while the other rod, that is to say the rod adjacent to the occupants left hand, is allowed to remain in rearwardly shifted or engaged position, then the canopy 71 may be swung upwardly or downwardly to the left about the left hand set of pintle elements 77 which then act as hinge pins. Similarly, if the left hand rod 76 is shifted forwardly while the right hand rod 76 is left in rearwardly shifted position, the canopy 71 may be swung and downwardly to the right. Finally, if both of the rods '76 are shifted forwardly, the canopy 71 is completely unlocked and can be pushed entirely away from closureforming position. This latter possibility is convenient in case of underwater emergencies and is also useful in complete removal of the canopy 71 for making repairs or adjustments on the marine vehicle A. In this connection, it should be noted that the canopy 71 is not tightly held in place or gasketed within the opening 70 and, furthermore, it will be noted that the bubble 72 is provided in its uppermost central area with two relatively large longitudinally extending slots 79 so that, when the marine vehicle A is submerged, the ambient water will enter and fill the occupant-compartment C. Thus, the occupant who is within the occupant-compartment C will actually be subjected to the same conditions of temperature and pressure which are existent in the body of water immediately outside the marine vehicle A.

Formed integrally with the hull 1 and extending laterally outwardly from each side thereof in the region of the for rotatably supporting rockshafts 88, 89, which project at opposite ends through the bearing sleeves 86, 87. At their external ends, the rockshafts 88, 89, are rigidly fixed in forward flippers 90, 91, the latter preferably being molded of resin bonded fiber glass or other similar material and having a streamlined contour which presents a smooth continuation of the curves of the fairing protrusions 80, 81. The rockshafts 88, 89, are coaxial and are located somewhat to the rear of the end walls 82, 83, of the fairing protrusions 80, 81, and the forward flippers 90, 91, and are of such size as to fit close to, but nevertheless be in free swinging relation to, the end walls 82, 83. Similarly fixed rigidly to and movable with the shafts 57, 58, at the rear of the hull 1 are rear flippers 92, 93, which are also preferably molded from resinbonded fiber glass and are of substantially streamlined contour, all as best seen in FIGS. 1 and 5.

Rigidly mounted upon the interior ends of the rockshafts 88, 89, are depending arms 94, 95, which are operatively seated in slots 96, 97, of bell-cranks 98, 99, the latter being located in the same horizontal plane and respectively pivoted upon vertical pins 100, 101, fixed in upstanding bosses 102, 103, formed upon the upwardly presented interior face of the bottom wall 4 of the hull 1. The bell-cranks 98, 99, extend forwardly and are swivelably connected to the outer ends of transverse actuator rods 104, 105, which are, in turn, at their inner ends operatively connected by ball-and-socket universal joints 106, 107, to a control stick 108. At its lower end, the control stick 108 is swivel-mounted in a ball-andsocket universal joint 109 which is rigidly bolted to an upstanding boss 110 secured upon the upper face of the bottom wall 4 of the hull 1 a short distance forward from the cross wall 2. Just above the universal joint 109, the control stick 108 is rigidly provided with a square horizontal plate 111 which is loosely engaged at its four corners by loosely depending studs 112, the latter being, in turn, loosely engaged within Vertical compression springs 113. The four compression springs 113 are rather precisely balanced as to strength and degree of compression and will normally hold the plate 111 in a predetermined position so that the control stick 108 is held firmly but resiliently in a predetermined neutral position. By this arrangement, the control stick 108 cam be swung forward and rearward or from side-to-side as well as into various intermediate positions, but, when released, will always return to neutral position. The control stick 108 is also provided with a rearwardly presented ball-and-socket joint 114 by which it is operatively connected to a rearwardly extending actuator rod 115. extending loosely through an aperture 116 in the front wall 61 of the platform P, and being, in turn, operatively connected at its rear end by means of a second ball-and-socket joint 117 to a link rod 118 slidably mounted in a watertight seal 119 and extending into the motor compartment 43 for operative connection by means of links 120, 121, to rockarms 122, 123, which are, in turn, respectively fixed upon the interior ends of the shafts 57, 58. It should be noted in this connection that the central or pivot point of the universal joint 117, the center point of the swivel connection between the bell-crank 98 and the actuator arm 104, and the central or pivot point of the swivel connection between the bell-crank 99 and the actuator rod 105 are all in the same plane as the central pivot point of the ball-and-socket joint 109 of the control stick 108. Consequently, when the control stick 108 is moved laterally to the right or the left, the forward flippers 90, 91, will be correspondingly shifted Without producing any movement of the rear flippers 92, 93. Similarly, foreand-aft movement of the control stick 108 will raise or lower the angulation of the rear flippers 92, 93, without producing any corresponding movement in the forward flippers 90, 91. It will also. be evident that by appropriate compound movement of the control stick 108, various degrees of simultaneous movement of all four flippers 90, 91, 92, 93, may be achieved. By this means, it is possible for the occupant to cause the marine vericle A to follow any desired forward course in the water. As a matter of fact, when submerged, the marine vehicle A, by proper manipulation of the control stick 108, can be made to bank, turn, dive, or ascend.

The ability of the marine vehicle A to dive and ascend solely in response to manipulation of the rear flippers 92, 93, without correspondingly flooding or emptying the ballast compartments 23, 24, is limited for reasons which will be presently more fully discussed.

Rigidly, but removably, mounted within the forward compartment 5 is a rectilinear hydrogen-oxygen fuel cell 124 which is operatively connected to a high-pressure supply tank 125 filled with hydrogen and a high-pressure supply tank 126 which is filled with oxygen. The ionic reaction between hydrogen and oxygen in the presence of a suitable catalyst within the fuel cell 124 is a rather recent, but nevertheless, well-understood development and is, therefore, not described in detail herein. It is sufficient for present purposes to note that the hydrogenoxygen fuel cell affords a comparatively light-weight source of electrical energy and is capable of producing practical quantities of electrical energy at substantial voltages and amperage's over a reasonably sustained period of time and the output of the fuel cell 124 is conventionally connected through the control rheostat 13 to the motor 44 to drive the marine vehicle A with considerable power. Ordinarily, it would require a very large amount of power generated at the propeller 50 to drive the marine vehicle A through the water at acceptable rates of speed, because of the frictional drag between the water and the external surfaces of the hull 1. It has been found, however, in connection with the present invention that it is possible to reduce power consumption greatly and obtain a remarkable increase in forward speed by covering all of the exterior surfaces of the hull 1 and the flippers 90, 91, 92, 93, with a novel skin substantially as shown in FIG. 10. The drag-reducing skin consists of an integument 127 formed of rubber or some rubber-like synthetic material which is adhesively or otherwise rigidly secured around its edges to the hull surface and is integrally provided on its interior face with a plurality of downwardly projecting spaced fingers or tines 128 which rest upon the hull surface and support the integument 127 in upwardly spaced relation thereto. The intervening space is filled under slight pressure with a hydraulic fluid 1. For this purpose, various light, low-viscosity oils or damping fluids have been found to be satisfactory. It is, of course, desirable and even preferable that such damping fluids exhibit minimal viscosity charges with respect to variations in tempera ture. Ordinary hydraulic brake fluid, for instance, of

the type commonly used in automobiles has been found to be excellent for this purpose. The space between the integument 127 and the hull surfaces is filled with fluid under suflicient pressure so that the integument 127 is tightly and smoothly stretched. This type of surface skin has been found to damp without surface turbulence and eliminate up to 60% of frictional drag. Consequently, the marine vehicle A will move very rapidly through the water under minimum power requirements.

Also rigidly, but nevertheless, removably disposed within the forward compartment 5 are two spherical supply tanks 129, 130, containing compressed air and being connected in tandem through an air supply line 131 to a conventional type of normally closed spring-biased air-pressure control valve 132 having an external actuating lever 133. The control valve 132 is mounted upon the side wall 21 and is connected'through a supply header 134 to the upper portions of both ballast tanks 23, 24. The upper portions of both ballast tanks 23, 24, are also mutually connected through a pressure relief header 135 to a conventional type of normally closed spring-biased air outlet valve 136 which is provided with an external actuating lever 137. The air outlet valve 136 is also mounted on the side wall 21 in forwardly spaced relation to and in horizontal alignment with the air-pressure control valve 132. As will be seen by reference to FIG. 12, the valves 132, 136, are located symmetrically on opposite sides of the arm 34 of the shaft 32 which is, in turn, rigidly provided with an upwardly extending rocking-arm 138, which, in its normal or neutral position, as shown, does not contact either of the actuating levers 133, 137. It will also be noted that when the rocking-arm 133 is in this neutral position, the shaft 32 will be in such position so that the slide valves 26 will be in the closed position shown in FIG. 9. If, however, the occupant grasps the hand rod 35 and pushes it forward rocking the shaft 32 in a counterclockwise direction (reference being made to FIG. 3), the initial movement will shift the slide valves 26 to open position and continued movement will cause the rocking-arm 138 to engage the actuating lever 133, thereby opening the air control valve 132 and admitting compressed air into the ballast tanks 23, 24, assuming that the marine vehicle A is submerged and the ballast tanks 23, 24, are filled with water, the admission of compressed air will blow the ballast tanks and cause the marine vehicle A to ascend. Since the slots 28 are wider than the slots 25, this valve actuating movement of the shaft 32 will still permit unimpeded flow of water out of the ballast tanks 23, 24, through the slots 25. On the other hand, if the marine vehicle A is floating on the surface of the water and the occupant desires to submerge the hand rod 35 may be pulled rearwardly rocking the shaft 32 in clockwise direction (reference again being made to FIG. 3) and accordingly the slide valves 26 will move in the opposite direction and again the slots 28 will come into valve-opened registration with the slots 25. However, the rocking-arm 138 will ulimately engage the actuating lever 137 of the air outlet 136 so that water may flood into the ballast tanks 23, 24, and the air which is normally entrapped therein will be expelled through the pressure relief header 135 which, incidentally, is connected to a discharge tube 139 extending through the keel K and opening exteriorly to the rear thereof, as shown in FIG. 3. It should also be pointed out that the bottom wall 4 of the hull 1 is provided with a plurality of water inlet apertures 146 which open into the occupant-compartment C so that the volumetric displacement of the occupant-compartment C will not contribute in any way to the buoyancy of the marine vehicle A. Finally, the volumetric displacement of the ballast tanks 23, 24, is balanced against the total weight and displacement of the marine vehicle A so that when the ballast tanks 23, 24, are fully blown, and the slide valves 26 closed, the marine vehicle A will float on the surface of the water with its flippers 90, 91, 92, 93, barely submerged. It, of course, must be borne in mind that the weight of the occupant, when aboard, will somewhat reduce this buoyancy and cause the marine vehicle A to ride somewhat lower in the water. As a practical matter, this reduction in buoyancy attributable to the presence of the occupant is not very great because the average human being will ordinarily float in sea water and will almost float in fresh water. The presence of the rubber diving suit and underwater breathing apparatus will reduce this natural buoyancy somewhat, but, since the occupant-compartment C is in open communication with the exterior body of water through the opening 140, these factors will have very little over-all effect on the marine vehicle A.

Thus, if the occupant desires to travel along the surface of the water it is simply necessary to keep the ballast tanks 23, 24, fully blown and turn on the motor 44 by appropriate manipulation of the rheostat 13. If the occupant will open the slide valves 26 and partially flood the ballast tanks 23, 24, so that the marine vehicle A is just barely submerged and then turn the motor 44 on while at the same time slowly pulling the control stick 108 to-and-fro in a fore-and-aft rocking movement, the alternate upward and downward angulation of the rear flippers 2, 93, will cause the marine vehicle A to successively dive and ascend as it travels forwardly in a sinuous path having remarkable resemblance to the swimming movements of a porpoise. This can be done solely for recreational and amusement purposes if desired, but becomes a very valuable deception-producing faculty where the marine vehicle A is being used for a military purpose.

It will, of course, be evident that by fully flooding the ballast tanks 23, 24, and at the same time pushing the control stick 108 directly forward, the occupant can cause the marine vehicle A to dive a substantial depth. Of course, the depth to which any scuba diver can go is limited by the capacity of the human body to withstand the compressive forces of the water at such depth and, therefore, the depth-pressure gauge should always be carefully observed to avoid the danger of driving beyond a reasonably safe depth-limit. Similarly, when the marine vehicle A is submerged, it is possible by blowing the ballast tanks 23, 24, to ascend to an upper level or to surface entirely as may be desired. The hydrogen-pressure gauge 1? and oxygen-pressure gauge 20, as well as the ammeter 11 and volt meter 12, serve to give the occupant a constant indication of the state of his fuel supply. The tachometer 10, bank and turn indicator 14, and directional compass 16 serve the useful and conventional navi gational purposes and the gauges 17, 18, atford the occupant an opportunity to avoid excessive or damaging pressures in the ballast tanks 23, 24.

When the occupant reaches the location in which he desires to carry out some underwater task, he can easily release the canopy 71 and swing it away from closed position enabling himself to crawl out of the occupantcompartment C and move around independently of the marine vehicle A. It will, of course, be understood that if this is done some conventional anchoring means must be provided to hold the marine vehicle A relatively stationary and prevent drifting with undersea currents. Otherwise, the occupant might become separated from the marine vehicle A after having left it and be unable to locate it again for purposes of return.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the underwater sleds may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A marine vehicle comprising:

a hull having a man-carrying compartment which is open to entry of water from the surrounding body of water in which the vehicle is located;

ballast tanks in said hull each having upper and lower portions and located on opposite sides of the mancarrying compartment, said tanks being adapted for providing sufficient buoyancy to maintain the vehicle afloat notwithstanding the presence of water in the man-carrying compartment;

manually controllable means movable in a given direction for admitting water into said ballast tanks for causing said vehicle to sink;

a waterproof housing in said hull;

an electric motor operatively mounted within said housand waterproof electric power-supply means operatively 9 connected to the electric motor for energizing said electric motor;

said vehicle further comprising a normally closed air outlet valve for said tanks;

means connecting said valve between the upper portions of said tanks and the exterior of the vehicle;

a control handle on said valve movable from a first position in which said valve is closed to a second position in which said valve is open;

and linkage means connected to the manually controllable means for engaging the control handle and moving the same to its second position upon the manually controllable means being moved in said given direction. 1

2. A marine vehicle comprising:

a hull having a man-carrying compartment which is open to entry of water from the surrounding body of water in which the vehicle is located;

ballast tanks in said hull located on opposite sides of the man-carrying compartment, said tanks being adapted for providing suflicient buoyancy to maintain the vehicle afloat notwithstanding the presence of water in the man-carrying compartment;

manually controllable means movable in a given direction for releasing water from said ballast tanks for causing said vehicle to rise;

a Water proof housing in said hull;

an electric motor operatively mounted within said housand waterproof electric power-supply means operatively connected to the electric motor for energizing said electric motor;

said vehicle further comprising a source of compressed arr; 1

a normally closed air inlet valve for said tanks;

means connecting said valve between the air source and said tanks;

a control handle on said valve movable from a first position in which said valve is closed to a second position in which said valve is open;

and linkage means connectedto the manually controllable means for engaging the control handle and moving the same to its second position upon the manually controllable means being moved in said given direction. I

3. A marine vehicle comprising:

a hull having a man-carrying compartment which is open to entry of water from the surrounding body of water in which the vehicle is located;

ballast tanks in said hull each having upper and lower portions and located on'opposite sides of the mancarrying compartment, said tanks being adapted for providing suflicient buoyancy to maintain the vehicle 10 afloat notwithstanding the presence of water in the man-carrying compartment;

manually controllable means movable in a first direction for admitting water into said ballast tanks and in a second direction for releasing water from said ballast tanks;

a water proof housing in said hull;

an electric motor operatively mounted within said housand waterproof electric power-supply means operatively connected to the electric motor for energizing said electric motor;

said vehicle further comprising a source of compressed air;

a normally closed air inlet valve for said tanks;

means connecting said air inlet valve between the compressed air source and said tanks;

a control handle on said air inlet valve movable between a first position in which said air inlet valve is closed and a second position in which said air inlet valve is open;

a normally closed air outlet valve for said ballast tanks;

means connecting said air outlet valve between said upper portions of said ballast tanks and the exterior of said vehicle;

a control handle on said air outlet valve movable from a first position in which said air outlet valve is closed to a second position in which said air outlet valve is and linkage means connected to the manually controllable means for engaging the air inlet valve control handle and moving the same to its second position when the manual control means is moved in said second direction and for engaging the air outlet valve control handle and moving the same to its second position when the manual control means ismoved in said first direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,823,636 Gongwer Feb. 18, 1958 2,830,109 Iusti Apr. 8, 1958 2,849,978 Durham Sept. 2, 1958 2,887,977 Piry May 26, 1959 2,989,937 Rondot June 27, 1961 3,043,898 Miller July 10, 1962 3,063,394 Rebikofi Nov. 13, 1962 FOREIGN PATENTS 591,010 Italy Apr. 11, 1959 1,111,049 Germany July 13, 1961 UNITED STATES PATENT- OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 131,664 May 5 1964 George W. McInvale It is hereby certified-that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below. I

Column 2, line 15 for "materails" read materials line 16, for "realtively" read relatively column 4 line 56, after "swung" insert upwardly Signed and sealed this 8th day of September 1964,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Altesting Officer Commissioner of Patents 

1. A MARINE VEHICLE COMPRISING: A HULL HAVING A MAN-CARRYING COMPARTMENT WHICH IS OPEN TO ENTRY OF WATER FROM THE SURROUNDING BODY OF WATER IN WHICH THE VEHICLE IS LOCATED; BALLAST TANKS IN SAID HULL EACH HAVING UPPER AND LOWER PORTIONS AND LOCATED ON OPPOSITE SIDES OF THE MANCARRYING COMPARTMENT, SAID TANKS BEING ADAPTED FOR PROVIDING SUFFICIENT BUOYANCY TO MAINTAIN THE VEHICLE AFLOAT NOTWITHSTANDING THE PRESENCE OF WATER IN THE MAN-CARRYING COMPARTMENT; MANUALLY CONTROLLABLE MEANS MOVABLE IN A GIVEN DIRECTION FOR ADMITTING WATER INTO SAID BALLST TANKS FOR CAUSING SAID VEHICLE TO SINK; A WATERPROOF HOUSING IN SAID HULL; AN ELECTRIC MOTOR OPERATIVELY MOUNTED WITHIN SAID HOUSING; AND WATERPROOF ELECTRIC POWER-SUPPLY MEANS OPERATIVELY CONNECTED TO THE ELECTRIC MOTOR FOR ENERGIZING SAID ELECTRIC MOTOR; SAID VEHICLE FURTHER COMPRISING A NORMALLY CLOSED AIR OUTLET VALVE FOR SAID TANKS; MEANS CONNECTING SAID VALVE BETWEEN THE UPPER PORTIONS OF SAID TANKS AND THE EXTERIOR OF THE VEHICLE; A CONTROL HANDLE ON SAID VALVE MOVABLE FROM A FIRST POSITION IN WHICH SIAD VALVE IS CLOSED TO A SECOND POSITION IN WHICH SAID VALVE IS OPEN; AND LINKAGE MEANS CONNECTED TO THE MANUALLY CONTROLLABLE MEANS FOR ENGAGING THE CONTROL HANDLE AND MOVING THE SAME OF ITS SECOND POSITION UPON THE MANUALLY CONTROLLABLE MEANS BEING MOVED IN SAID GIVEN DIRECTION. 